THE ANTHRAX FLY 171 



This, for instance, is the Amophila-grub's way of devouring 

 its caterpillar. A hole is made in the victim's side, and the 

 head and neck of the grub dives deep into the wound. It 

 never withdraws its head, never pauses to take breath. The 

 voracious animal always goes forward, chewing, swallowing, 

 digesting, until the caterpillar's skin is empty. Once the meal 

 is begun, the creature does not budge as long as the food lasts. 

 If moved by force it hesitates, and hunts about for the exact 

 spot where it left off eating ; for if the caterpillar be attacked 

 at a fresh point it is liable to go bad. 



In the case of the Anthrax-grub there is none of this 

 mangling, none of this persistent clinging to the original 

 wound. If I tease it with the tip of a pointed brush it at once 

 retires, and there is no wound to be seen on the victim, no 

 sign of broken skin. Soon the grub once more applies its 

 pimple-head to its meal, at any point, no matter where, and 

 keeps itself fixed there without any effort. If I repeat the 

 touch with the brush I see the same sudden retreat and the 

 same calm return to the meal. 



The ease with which this larva grips, leaves, and regrips 

 its victim, now here, now there, and always without a wound, 

 shows that the mouth of the Anthrax is not armed with fangs 

 that can dig into the skin and tear it. If the flesh were gashed 

 by pincers of any kind, one or two attempts would be necessary 

 before they could leave go or take hold again ; and besides, 

 the skin would be broken. There is nothing of the kind : the 

 grub simply glues its mouth to its prey, and withdraws it. 

 It does not chew its food like the other flesh-eating grub : it 

 does not eat, it inhales. 



This remarkable fact led me to examine the mouth under 

 the microscope. It is a small conical crater, with yellowish- 

 red sides and very faint lines running round it. At the bottom 

 of this funnel is the opening of the throat. There is not the 

 slightest trace of mandibles or jaws, or any object capable of 

 seizing and grinding food. There is nothing at all but the 

 bowl-shaped opening. I know of no other example of a mouth 



